The fluid extracted from a borehole or oil well is usually a mix of numerous materials, including sand, rocks, mud, water, oil, gas and possibly other materials, some of which it is possible to mechanically filter out.
As no two oil wells are identical, the output and quality or state of the fluid extracted from the well is different for each specific oil well. However, one thing is common for all oil wells, namely, that the fluid comprises a mix of water and oil. When retrieving fluid from an oil well or borehole, the retrieved fluid comprises oil mixed with, usually, a considerable amount of water. This is not a desirable mix, as the water in this context may be considered a contamination, or unwanted part, of the fluid extracted from the oil well.
The water separated from the fluid from the oil well is usually to be disposed of in an environmentally safe manner. If the remainder of the fluid is to be pumped into the sea surrounding an oil rig, there may be specific requirements set by laws requiring the content of oil in the water to be below a certain level.
As outlined above, there is a need for an efficient method and/or device for separating oil from the oil/water mix from an oil well.
Publications such as EP 0544 059A, U.S. Pat. No. 4,425,239, U.S. Pat. No. 1,920,468, U.S. Pat. No. 2,826,306, U.S. Pat. No. 5,730,871, U.S. Pat. No. 6,074,557, U.S. Pat. No. 6,080,312 and U.S. Pat. No. 6,730,236 describe devices and method for separating two liquid mediums. Reference is made to the above US patent publications, all of which are hereby incorporated in the present specification by reference in their entirety for all purposes.